Coils Project Page 1

Here are some examples of the type of Coils that I was originally trying to wind. I thought that it would be great to have a set form (bobbin) and wind on that. I used PVC pipe for the core and Plexi-Glass for the flanges.

It worked quite well. I used 1/4 inch plexi and the form was quite strong. Goop glue works great to fasten everything securely. No chance of these babies coming apart here! I was impressed with the way these worked out but...

This idea was bad on several levels as I later learned. Wall thickness is a huge detractor from the coil performance. I have since learned that winding the coil out to the very edge of the core is often most desired in our applications. Also, these are round cores, so I had planned on using bolts ...bad again, as they are one solid piece of metal and cause a lot of eddy currents. This results in tremendous losses in the system. Plus the head on the bolt and the nut on the other end... all play a huge part in the "wall thickness" problem. Using these as air cores... sure, they're awesome! But not very good for effecient pulse motors.

Another brilliant idea to use iron filings from old brake rotors. I thought instead of using bolts for my cores, I could use the filings. I have never really tried to make coils with these, but I can imagine that they would perform better than the bolts, though I have no data to back that up. Anyone want to try it and let me know?

Here is a picture of just some of the wire that I have. I have a lot more to the left under a larger bench.

Notice my winding jig that I made, in the top of the picture (yes it's cut off, because I never intended on speaking about it in this picture.) But if you'd like to learn more about my winding jig and how I made it, please Click Here: http://oupower.com/index.php?dir=_My_Projects/_Shop_Projects/Winding_Jig

This is one of the new Winding Jigs that I designed. It's nothing special at all. Merely a steel plate with a interchangable core.

The design is simple and easy. It allows me to wind huge coils all the way out the the very end of the core material. This particular jig is designed for "I" type laminations. I stack 36 of them on top of each other, to make a 1/2 inch square core. I have 2 sets of laminations ...one set is 1.5 inches in length, and the other is 3 inches in length. You can see a 3 inch jig core laying on the table beside my drill chuck tightener. It has the 1.5 inch core in the jig now.

I advise stopping every few turns and putting a good layer of tape in there. The tape helps to support the coil. I have only used larger gauge wire in these "Self supporting" coils. I am not sure that smaller gauge wire would work well. It may spring out too much when finished?

A big trick I learned was to take 4 of the laminations that I use for the core, and place them directly in contact with the core form. You make a box around your core that way. These 4 laminations then allow you to push the form out as you are pushing the real laminations in. I surround the 4 lams with paper as it is a good insulator. See below to view the coil with the laminations inserted in there.

Note that I use a calculator for my counter! -eh? What in the hell? Click Here to see what I did: http://oupower.com/index.php?dir=_My_Projects/_Shop_Projects/Winding_Jig

This is the coil that I spoke of. I only wound a few hundred turns on this one, as I wanted to test the concept. It worked perfectly! If you do not use the 4 extra laminations as described above, the paper crumples as you push in the real core of 36 laminations.

The 4 extra lams provide the perfect thing to reinforce the center as you push the form out and the lams in.

How do you do that? See below as I show you

Also the 4 extra lams, get rid of the sharp corner problems of the normal lamination core. You have much rounder corners using this method